title: Cellobiose dehydrogenase of Chaetomium sp. INBI 2-26(-): structural basis of enhanced activity toward glucose at neutral pH.
abstract: Cellobiose dehydrogenase (CDH) is an extracellular fungal flavocytochrome specifically oxidizing cellooligosaccharides and lactose to corresponding (-lactones by a variety of electron acceptors. In contrast to basidiomycetous CDHs, CDHs of ascomycetes also display certain activity toward glucose. The objective of this study was to establish the structural reasons of such an activity of CDH from mesophilic ascomycete Chaetomium sp. INBI 2-26 (ChCDH). The complete amino acid sequence of ChCDH displayed high levels of similarity with the amino acid sequences of CDHs from the thermophilic fungi Thielavia heterotallica and Myriococcum thermophilum. Peptide mass fingerprinting of purified ChCDH provided evidence for the oxidation of methionine residues in the FAD-domain. Comparative homology modeling of the structure of the ChCDH FAD-domain in complex with the transition state analog based on the structure of the same complex of basidiomycetous CDH (1NAA) as template indicated possible structural reasons for the enhanced activity of ascomycetous CDHs toward glucose at neutral pH, which is a prerequisite for application of CDH in a variety of biocompatible biosensors and biofuel cells.
authors.affiliation: A.N.Bach Institute of Biochemistry, Russian Academy of Sciences, Moscow, Russia.
authors.forename: Liliya G
authors.initials: LG
authors.lastname: Vasilchenko
authors.forename: Karen N
authors.initials: KN
authors.lastname: Karapetyan
authors.forename: Olga P
authors.initials: OP
authors.lastname: Yershevich
authors.forename: Roland
authors.initials: R
authors.lastname: Ludwig
authors.forename: Marcel
authors.initials: M
authors.lastname: Zamocky
authors.forename: Clemens K
authors.initials: CK
authors.lastname: Peterbauer
authors.forename: Dietmar
authors.initials: D
authors.lastname: Haltrich
authors.forename: Mikhail L
authors.initials: ML
authors.lastname: Rabinovich
mesh_terms: D000595:Amino Acid Sequence; D002237:Carbohydrate Dehydrogenases / Q000737:chemistry / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D002597:Chaetomium / Q000201:enzymology*; D005947:Glucose / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D008969:Molecular Sequence Data; D016415:Sequence Alignment; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D002237:Carbohydrate Dehydrogenases; C019859:cellobiose-quinone oxidoreductase; D005947:Glucose